225304021 has 4 divisors (see below), whose sum is σ = 235099872. Its totient is φ = 215508172.

The previous prime is 225304003. The next prime is 225304091. The reversal of 225304021 is 120403522.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120403522 = 2 ⋅60201761.

It is a cyclic number.

It is not a de Polignac number, because 225304021 - 2¹⁹ = 224779733 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 225304021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225304091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4897891 + ... + 4897936.

It is an arithmetic number, because the mean of its divisors is an integer number (58774968).

Almost surely, 2^225304021 is an apocalyptic number.

It is an amenable number.

225304021 is a deficient number, since it is larger than the sum of its proper divisors (9795851).

225304021 is an equidigital number, since it uses as much as digits as its factorization.

225304021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9795850.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 225304021 is about 15010.1306123564. The cubic root of 225304021 is about 608.4940195444.

Adding to 225304021 its reverse (120403522), we get a palindrome (345707543).

The spelling of 225304021 in words is "two hundred twenty-five million, three hundred four thousand, twenty-one".